Apparatus for introducing melts into casting molds



Oct. 26, 1937. J. A. RO N 2,095,998

APPARATUS FOR INTRODUCING MELTS INTO CASTING MOLDS Filed Nov. 21, 1935Patented Oct. 26, 1937 UNITED STATES PATENT OFFICE.

- .aoaaass INTO CASTING MOLDS Jens Aalcrg Riim Skive, fienm'ark,assignorto W. Hellesen and 00., Copenhagen, Denmark Application November21. 1935, Serial No. 50,962

In Germany November 22, 1934 8 Claims. (01. 22-571 This inventionrelates to improvements in apparatus for, introducing melts into castingmolds, especially for dental purposes and has for its main object toprovide for a simple and cheap apparatus, which enables theinstantaneous produce tion apparatus fitted with a piston,'on which thecasting mold sits. When the piston is drawn out the melt which lies onthe casting mold is sucked into the mold. lThese known apparatusdo notfulfil the demands made upon them, especially when it is a matter ofproducing objects with especially thin walls such as plates for the roofof the mouth.

The vacuum produced by the piston is not sumcientlygreat to produce inevery case bubble-free castingswhich exactly reproduce the model. The

piston cannot even with the greatest care be made to slide exactly inthe cylinder so that the requisite high vacuum is produced andmaintained. sufllci'ently long. The apparatus loses its tight fit withincreasing use and its life is in consequence short.

- The apparatus according to the present inven-'- tion obviates allthese disadvantages. It consists essentially of two hollow cylindersopen at one 'end which slide one within the other, one of whichcanbemade to move in respect to the other by means of the action of a springfor example, and

one or which is connectedto the casting mold. The hollow space insidethe two cylinders contains a liquid filling, in particular oil.

One embodiment of the invention is illustrated in section in thedrawing. e

i The mold support I in which the mold is formed in the usual way bymeans of a wax model -and porous embedding material, has a projectingpart 2 witha conical interior which fits a cone 3 in the head 4 .of theinner hollow cylinder 5, which is. open at the base, A channel 6 formedround the cone 3 in the head 4 serves to hold oil orthe like Y whichacts as acaulking medium. In this channel 6 there'is also airing l witha handle l,'=which;

serves to lift oi! the mold support I after the cast ing has beencompleted. Two handles 9 are further provided in the head for settingthe apparacylinders can be placed tus under tension. The head 4also'carries a pro-' tecting tube III, to whicha worktable II is fixed.The -hollow cylinder 5 is inserted into a hollow cylinder I! open at thetop, the base ii of which is screwed into the foot I or the apparatus. A5 1 spring I5 is positioned in the hollow space and formed by thecylinders Sand l2 and filled with oil or other liquid. This spring isput under tension when the cylinder 5 is moved downwards and ismaintained in this position by a foot-pedal lev- 10 er l8 whichoscillates about a pin l1 and is held by a'spring l6, and which gripsover a ring shaped shoulder 19 which is fixed to the protecting tube IIIwhich is joined tothe head l. The lower part 20 of the shoulder l9 worksin connection with a 15 shoulder 2| on the outer surface of the cylinderl2.

The modus operandi oflthe apparatus is as fol-v lows: The twohollowcylinders 5 and II are pushed together bymeans of the handles 9,.so that the 20 spring 15 is put under tension. The lever l8 catchesover the shoulder I!) so thatthe spring It remains in position. The moldsupport I, which carries the mold previously prepared by means of-a waxmodel and porous embedding ma- 5 4 terial, islfittedi over the cone 3 ofthe apparatus for producing the vacuum, oilor another liquid being runinto the channel 5. Molten metal is introduced into a trough in theupper surface of...

the mold. Theeonnection-betwen the cylln' g0- de'rs 5 and I2 isbroken byapplying pressure on the lever l8. The spring I5 is released and pressesthe cylinder 5 upwards in the cylinder l2 until .the. shoulder 20 abutsagainst the shoulder 2 I. A

vacuum is therefore produced in the mold so that 35 the metal is suckedinto the mold. When the casting is cold, themold support 'I and the moldand casting are freed from the cone 3 by turning the ring I by means ofthe handle 8 The invention is-not restricted to the example 4 hereindescribed. For example the inner spring can be replaced by an outerspring. The drawing apart of-the two cylinders can be achieved with outaspring by-m'eans of a weight which is attached to the outer cylinderand when released by 4 a catch moves downwards while the inner cylinderremains stationary, for example-is fixed with v theaid oftheprotectingtubetothe wall or a -work-bench. In this case therefore theouter cylindexwhich is open-at thetopismonble and not 0 theinnercylinder which is open at thebottom as isthecase both 7 of vertically.Theconnectionbetween'themoldsum.

port and can 2 4 also be arranged difierently, for example 'by means oi'a tube or hose in which case the mold support can stand on thework-bench.

. be'applied for making castings of metals or The apparatus described isapplicable not onlyfor dental purposes. It can also be used for castingjewelry, machine parts and the like; It can other castable materialsgenerally.

I claimr 1. An appliance for use in, making castings comprising twovertical hollow cylinders open atopposite ends, one of said cylinderssliding withi in the other cylinder, a columnof liquid in the hollowspace formed by said two cylinders, means for connecting the.upper part-01" said hollow space formed by said cylinders with a casting mold and aspring moving one of said cylinders relative to the other cylinder. i

2. Appliance for use in making-castings comprising a. hollow cylinderopen at the top, a foot connected with the-bottom of said hollowcylinder', another hollow cylinder open at the bottom slidably fitted insaid first hollow cylinder, means for connecting the upper part of thehollow space formed by said cylinders with a mold arranged on the topcover oi. 'said second cylinder, a column of liquid in said hollowspace, a spring arranged in said hollow space and releasable means formaintaining both cylinders in telescoped conditions with said springunder tension.

3. An appliance for use in making castings comprising a hollow cylinderopen at, the top, a

foot connected with the bottom of said cylinder,

another hollow cylinder open at the bottom slidably fitted in said firsthollow cylinder, a protecting tube connected with said second innercylinder and surrounding said first outer cylinder,

means for connecting the upper part of the hollow space formed by saidcylinders with a mold arranged on thetop cover of said second cylinder,a column of liquid in said hollow space, 'a spring arranged in saidhollow space and releasable means for maintaining both'cylinders in telescoped condition with said spring under tension.

4. An appliance for use in making castings comprising a hollow cylinderopen at the top, a-

- foot connected with the bottom of said'hollow ranged in said hollowspace, and releasable means,

cylinder, another hollow cylinder open at the bottom slidably fitted insaid first hollow cylinder, a protecting tube connected with said innercylinder and surrounding said outer cylinder, handles connected withsaid inner cylinder, means for connecting the upper part of said hollowspace formed by said cylinders with a mold arranged on the top cover ofsaid second cylinder, 9. column of liquid in said hollow space, a springaradapted'to lock said cylinders in telescoped posi- .tion, means forconnecting the hollow space formed by said cylinders with a castingmold, a column of liquid in said upper part of the hollow space and aspiral spring arranged in said hollow space. Y

' 6. An appliancefor use in making castings comprising a hollow cylinderopen at the top,

a a foot connected with the bottom of said hollow cylinder, anotherhollow cylinder open at the bot- .tom slidably fitted in said firsthollow cylinder, a protectingtube connected with said inner cylinder andsurrounding said outer cylinder, handles'connected with said innercylinder, a shoulder at the lower end of said protecting tube, a foot-'pedal leveron said foot cooperating with said shoulder adapted to locksaid cylinders in telescoped position, a conical mold carrier 'in thecover of said inner cylinder, a longitudinal bore in' said carrier incorrespondence with the bore in said cover leading to the hollow spaceformed by said cylinders, a column of liquid in, said hollow space and aspiral spring arranged in 'said hollow space.

- 7. An appliance for use in making castings comprising a hollowcylinder open at the top, a foot connected with the bottom of saidhollow cylinder, another hollow cylinder open at the bottom slidablyfitted in said first hollow cylinder, a protecting tube connected withsaid'inner cylinder and surrounding said outer cylinder, handles.

connected with said inner cylinder, a shoulder at the-end of saidprotecting tube, a foot-pedal lever 'on 'said foot cooperating -withsaid shoulder ing to the hollow space formed by said cylinders,

with an axial aperture therethrough and an annular upwardly openingchannel adapted to concylinde'r. space, a cylindrical jacket secured insaid head and forming an enclosure around said outer cylinder, ashoulderat the bottom end 'of said Jacket, a treadle pivotally mountedon the base and adapted to engage said shoulder in order to retain thejacket in the slidable cylinder in the lowered position, stops on saidouter cylinder adapted to cooperate with said shoulder to limit theupward movement of said jacket and slidable cylinder, a ring fitted insaid channel and a mold tain a caulkingsubstance, a compression springacting between said base and said head in the support having a shankengaging in said channel in said head, means for locking the ring tosaid head, other means on said head for manually lowering the head withthe jacket and slidable cylinder in order to compress the spring and aliquid column filling the space within said slidable cylinder.

- anus Mama Bdrm.

